Long Range orders in multiferroics

TL;DR

This paper introduces a third long-range order in multiferroics that enhances electric polarization by reducing symmetry constraints, leading to a new understanding of polarization mechanisms.

Contribution

It proposes a novel long-range order in multiferroics that modifies the symmetry and significantly increases electric polarization, with a new polarization formula derived.

Findings

Electric polarization is increased by an order of magnitude.

A new form of electric polarization involving a third long-range order.

Symmetry reduction explains the enhanced polarization.

Abstract

We proposed that in multiferroics there exists a third long range order besides the electric polarization and magnetic order. This long range order reduces the symmetry of the spatial part of the wave functions of electrons. Thus the cancellation in the spin current" model can be avoided. As a result, the expectation value of electric polarization will be larger by an order of magnitude. We have derived a new form of electric polarization \vec{P} -\vec{Q}\times(\vec{s_i}\times\vec{s_{j+1}}) where \vec{Q} is the wave vector of this long range order